The table_io_waits_summary_by_table
Table
The table_io_waits_summary_by_table
table aggregates all table I/O wait events, as generated by the wait/io/table/sql/handler
instrument. The grouping is by table.
TRUNCATE TABLE
is permitted for summary tables. It resets the counters to zero rather than removing rows. Truncating this table also truncates the table_io_waits_summary_by_index_usage
table.
The table_io_waits_summary_by_table
table has these grouping columns to indicate how events are aggregated: OBJECT_TYPE
, OBJECT_SCHEMA
, and OBJECT_NAME
. These columns have the same meaning as in the events_waits_current
table. They identify the table to which the row applies.
table_io_waits_summary_by_table
has the following summary columns containing aggregated values. As indicated in the column descriptions, some columns are more general and have values that are the same as the sum of the values of more fine-grained columns. For example, columns that aggregate all writes hold the sum of the corresponding columns that aggregate inserts, updates, and deletes. In this way, aggregations at higher levels are available directly without the need for user-defined views that sum lower-level columns.
COUNT_STAR
,SUM_TIMER_WAIT
,MIN_TIMER_WAIT
,AVG_TIMER_WAIT
,MAX_TIMER_WAIT
These columns aggregate all I/O operations. They are the same as the sum of the corresponding
andxxx
_READ
columns.xxx
_WRITECOUNT_READ
,SUM_TIMER_READ
,MIN_TIMER_READ
,AVG_TIMER_READ
,MAX_TIMER_READ
These columns aggregate all read operations. They are the same as the sum of the corresponding
columns.xxx
_FETCHCOUNT_WRITE
,SUM_TIMER_WRITE
,MIN_TIMER_WRITE
,AVG_TIMER_WRITE
,MAX_TIMER_WRITE
These columns aggregate all write operations. They are the same as the sum of the corresponding
,xxx
_INSERT
, andxxx
_UPDATE
columns.xxx
_DELETECOUNT_FETCH
,SUM_TIMER_FETCH
,MIN_TIMER_FETCH
,AVG_TIMER_FETCH
,MAX_TIMER_FETCH
These columns aggregate all fetch operations.
COUNT_INSERT
,SUM_TIMER_INSERT
,MIN_TIMER_INSERT
,AVG_TIMER_INSERT
,MAX_TIMER_INSERT
These columns aggregate all insert operations.
COUNT_UPDATE
,SUM_TIMER_UPDATE
,MIN_TIMER_UPDATE
,AVG_TIMER_UPDATE
,MAX_TIMER_UPDATE
These columns aggregate all update operations.
COUNT_DELETE
,SUM_TIMER_DELETE
,MIN_TIMER_DELETE
,AVG_TIMER_DELETE
,MAX_TIMER_DELETE
These columns aggregate all delete operations.